We could consume a web service in .Net and get back the results sucessfully if there are no date fields in the output parameters. The issue is when there is a date field in the output parameters with NULL value, the web service is throwing error "String was not recognized as a valid DateTime". Even though the RFC is has no value in the date fields the web service shows '0000-00-00' as date format. And there are no trace of this issue in SOAMANAGER or SRT_UTIL. We identified that the DATE data types are not convereted to strings in the web service (it does convert all data types to strings in SAP_BASIS 701) and causing issues. Take a look at the diffrence in WSDL lines for date fields in 701 and 702.